A particle with momentum p0, mass m0 and energy E0 decays into two particles with mass m1 and m2. Find the energy of the particle E1 and E2.
The Attempt at a Solution
I calculated the energy of particle 1 in S' (system where particle 0 is at rest) in dependence of m0', m1', m2'. I got also the momentum of the particle 1 in system S' which I can write in dependence of m0', m1', m2' and E1'. For example I have taken the coordinates of system S' in such a way, that I can write the momentum p'1 of particle 1 as: p'1=(0,py',0) with py'=sqrt(f(m0',...)). Thus getting the four-momentum of particle 1: (E', 0, c*py', 0)
Well, what my question concerns. How can I translate the whole thing back into system S? Lorentz-Transformation or is there a easyer way? How can I go on to fullfill the task?